Cordless telephone systems are widely used in residential and small office environments. A cordless telephone replaces a standard wired phone set where the phone is directly connected to a telephone line by, for example, a twisted wire pair. In a cordless phone, or more generally, a local wireless telephone system, a base station interfaces with a telephone system, and provides a wireless radio interface for a corresponding wireless handset.
As with many types of electronics, local wireless telephony systems have evolved from relatively simple cordless systems to increasingly more complex and sophisticated systems that can perform additional functions and allow users to customize the system and handsets. One way of accessing and setting up system preferences and handset access control is to allow a handset to operate as in master mode. A handset operating as a master device in master mode acts somewhat like a remote control, where the handset interface provides a user with input and output means to interact with the base station over the local wireless telephony interface to view and control, set, re-set, configure, etc. various aspects of the system.
As popularity of these systems has grown, industry and governments have standardized aspects of these systems. In particular, the radio air interface has been standardized, and several different standards exist that define radio interface aspects, such as operating frequencies, frequency bands, channel frequency bandwidth, modulation technique, power levels, and so on. Standardization can allow expansion of systems, where, for example, a system sold with one handset can be configured to support multiple handsets, where each handset registers or subscribes to the same base station, allowing any one of the subscribed handsets to operate with the base station. Registration allows the base station to identify subscribed handsets so as not to interact with non-registered handsets, which could otherwise allow unauthorized access to the telephone service through the base station. As such, there is an ever present need for increased functionality and control of such systems.